Modular system for controlling usability of a device

1. System for controlling usability of an electronic device, which device comprises a processing unit, the system comprising a first control module, adapted to be connected to the processing unit, said first control module comprising a modem for communicating with a wireless communication network, and an access circuit connected to the modem for access to said wireless communication network, which access circuit comprises a first secure element; a second control module comprising a second secure element, configured to communicate with the first secure element over a communication link; wherein said access circuit is configured to set a usability state dependent on communication between the first secure element and the second secure element, and to control the device in accordance with said usability state; wherein the first control module is configured to authenticate the second control module, and to enter an alert state either if the second module is not connected or not authenticated, wherein operation of the processing unit is inhibited in said alert state so as to partially or fully disable the electronic device.

2. The system of claim 1 , wherein the first control module is configured to detect an identifier signal from the second control module responsive to the second control module being in connection with or within communication range of the first control module.

3. The system of claim 1 , wherein the access circuit is configured to challenge the second secure element by means of the first secure element, and to receive a challenge response from the second secure element.

4. The system of claim 3 , wherein the first control module is configured to send data comprising the challenge response to a server through the wireless communication network, using said modem, for validating the identity of the second module.

5. The system of claim 4 , wherein the first control module is configured to retrieve access data from the server through the wireless communication network, using said modem, for authenticating towards the second module.

6. The system of claim 1 , wherein the first control module is configured to authenticate the second control module over said communication link by means of access data associated with the second secure element.

7. The system of claim 6 , wherein the usability state is set dependent on successful authentication with respect to the second control module.

8. The system of claim 6 , wherein the first control module is configured to transmit data to the second control module dependent on the state set.

9. The system of claim 1 , wherein the access circuit is configured to realize a state machine which is configured to set one of a plurality of predetermined usability states including at least a normal state and an alert state, wherein operation of the processing unit is inhibited in said alert state so as to partially or fully disable the device.

10. The system of claim 1 , wherein the first control module is attached to or integrated in the device, and wherein the second control module is attached to or integrated in an accessory unit which is operably connectable to the device.

11. The system of claim 1 , wherein the first and the second control modules are configured to communicate over a short-range wireless or wired communication link.

12. The system of claim 1 , wherein the electronic device is battery powered, wherein the first control module is integrated in the electronic device, and wherein the second control module is integrated in a removable battery for powering the electronic device.

13. Method for controlling usability of an electronic device which comprises a processing unit, by means of a first control module connected to the processing unit, which first control module comprises a modem for communicating with a wireless communication network, and an access circuit connected to the modem for accessing said wireless communication network, which access circuit comprises a first secure element, comprising the steps of: receiving in the first secure element, an identifier signal from a second control module comprising a second secure element, over a communication link; realizing a state machine in the access circuit; authenticating the second control module; setting a usability state in the state machine, dependent on communication between the first secure element and the second secure element over the communication link, including entering an alert state either if the second module is not connected or not authenticated; and controlling the device in accordance with said usability state, wherein operation of the processing unit is inhibited in said alert state so as to partially or fully disable the electronic device.

14. The method of claim 13 , comprising the steps of: challenging the second secure element by means of the first secure element; obtaining a challenge response from the second secure element; identifying the second module based on the challenge response.

15. The method of claim 14 , comprising the steps of retrieving data from a server through said wireless communications network based on the challenge response, using said modem; obtaining access data based on the retrieved data, usable for authenticating the first secure device with the second secure device.

16. The method of claim 13 , comprising the step of: detecting an identifier signal from the second control module responsive to the second control module being in connection with or within communication range of the first control module.

17. The method of claim 13 , wherein the first control module is attached to or integrated in the device, and wherein the second control module is attached to or integrated in an accessory unit which is operably connectable to the device.

18. The method of claim 13 , wherein the electronic device is battery powered, wherein the first control module is integrated in the electronic device, and wherein the second control module is integrated in a removable battery for powering the electronic device.

19. An electronic device, comprising a processing unit; a first control module, connected to the processing unit, said first control module comprising a modem for communicating with a wireless communication network; and an access circuit connected to the modem for access to said wireless communication network, which access circuit comprises a first secure element; wherein the first secure element is configured to communicate with a second control module comprising a second secure element over a communication link; wherein said access circuit is configured to set a usability state dependent on communication between the first secure element and the second secure element, and to control the device in accordance with said usability state; wherein the first control module is configured to authenticate the second control module, and to enter an alert state either if the second module is not connected or not authenticated, wherein operation of the processing unit is inhibited in said alert state so as to partially or fully disable the electronic device.

20. The electronic device of claim 19 , wherein the first control module is configured to detect an identifier signal from the second control module responsive to the second control module being in connection with or within communication range of the first control module.